The poiseuille (symbol Pl) has been proposed as a
derived SI unit
SI derived units are units of measurement derived from the
seven base units specified by the International System of Units (SI). They can be expressed as a product (or ratio) of one or more of the base units, possibly scaled by an appropriate p ...
of
dynamic viscosity, named after the French physicist
Jean Léonard Marie Poiseuille
Jean Léonard Marie Poiseuille (; 22 April 1797 – 26 December 1869) was a French physicist and physiologist.
Poiseuille was born in Paris, France, and he died there on 26 December 1869.
Fluid flow
From 1815 to 1816 he studied at the École Po ...
(1797–1869).
In practice the unit has never been widely accepted and most international standards bodies do not include the poiseuille in their list of units. The third edition of the
IUPAC Green Book
''Quantities, Units and Symbols in Physical Chemistry'', also known as the ''Green Book'', is a compilation of terms and symbols widely used in the field of physical chemistry. It also includes a table of physical constants, tables listing the pr ...
, for example, lists Pa⋅s (
pascal-
second) as the SI-unit for dynamic viscosity, and does not mention the poiseuille.
The equivalent CGS unit, the
poise, symbol P, is most widely used when reporting viscosity measurements.
:
Liquid water has a viscosity of at at a pressure of ( = = = ).
["Viscosity of Liquids", in CRC Handbook of Chemistry and Physics, 91st Edition, W.M. Haynes, ed., CRC Press/Taylor and Francis, Boca Raton, Florida, 2010–2011.]
References
Bibliography
* François Cardarelli (2004). ''Encyclopaedia of Scientific Units, Weights and Measures''. Springer-Verlag London Ltd.
SI units
Units of dynamic viscosity
{{Measurement-stub